Negative Split a 3:15 Marathon (Read 695 times)

I'm not sure why there's such a fascination or desire to aim for a negative split in a marathon. I've always tried to run even pace the entire way. If I run a negative split it's usually because I ran a better than average race, not because I planned it that way. Knowing it takes a lot more effort to run 7:00 for mile 20 than it did for mile 1, the thought of speeding up at that point is daunting. If I can hang on and continue to run my pace, I'm doing well.

I'm not sure why there's such a fascination or desire to aim for a negative split in a marathon.

Because its infinitely less painful and requires a lot less recoverey that a positive split or a max effort even split marathon? I've ever done it that way but its not hard to understand the allure of that approach, especially for people like bhearn who run a lot of marathons and not all of them as100% max efforts.

I'm not sure why there's such a fascination or desire to aim for a negative split in a marathon. I've always tried to run even pace the entire way. If I run a negative split it's usually because I ran a better than average race, not because I planned it that way. Knowing it takes a lot more effort to run 7:00 for mile 20 than it did for mile 1, the thought of speeding up at that point is daunting. If I can hang on and continue to run my pace, I'm doing well.

If you plan for an evenly paced race and run positive, things probably went badly (and slowly, and painfully at the end).

If you plan for an evenly paced race and run negative, you probably had a great, fast race and perhaps a PR.

If you plan for an evenly paced race and run evenly congrats, you won the lottery and guessed perfectly to your fitness and conditions.

Framed that way, I'm not sure why it would be hard to understand the allure of negative splits. Typically one starts a marathon early in the morning with little warmup. As you go along your body gets warmed up, and you drop weight as you burn fuel and lose water weight (you can lose a few lbs and it will actually make you faster, up until the point where you start to get dehydrated to where it affects your ability to run well). So there is physiological rationale to support why you would run faster in the middle or towards the third quarter of the race than you did in the opening miles (contributing to a negative split).

As I said, there is some guesswork involved in determining your pace on race day. Running a positive split is a lucky feat unless you are running a sub-all-out effort (anyone can pick a slower pace than they are capable of and just click off the splits). You are far, FAR more likely to have a good race by going out a bit conservatively and speeding up if fitness/conditions allow, than by going out at what ends up to be a bit too fast and crashing to a positive split.

"If you want to be a bad a$s, then do what a bad a$s does. There's your pep talk for today. Go Run." -- Slo_Hand

Perhaps an expert will correct me, but I don't believe we burn a significant amount of muscle in a marathon. We do burn more fat as glycogen stores deplete.

Logic says that you're right; lowered glycogen stores make it harder to run as fast late in a race. But in practice, negative splits are an effective strategy, for amateurs as well as elites. Attempting to run a slight negative split is a more conservative strategy than trying for strictly even splits, because if you're a little wrong in your estimate, the potential blowup is not as bad. 7:30 / 7:30 pace instead of a desired 7:30 / 7:25 is a lot better than 7:27.5 / 7:45.

Because its infinitely less painful and requires a lot less recoverey that a positive split or a max effort even split marathon? I've ever done it that way but its not hard to understand the allure of that approach, especially for people like bhearn who run a lot of marathons and not all of them as100% max efforts.

??? Negative splits is often touted as the method to run an optimum time, so I don't see how it would require less recovery, though I can see that it may be less painful than a positive split, which often is the result of crashing late in a race. If running less than 100% max effort, I wouldn't think it mattered whether one ran positive, negative, or even splits. I see nothing inherent in negative splits that would make that the preferred way to run sub-maximal effort races.

Because its infinitely less painful and requires a lot less recoverey that a positive split or a max effort even split marathon? I've ever done it that way but its not hard to understand the allure of that approach, especially for people like bhearn who run a lot of marathons and not all of them as100% max efforts.

^^ +1 this. I've never done one (negative split) either. Of course, I've only done 5 in total. And my first and fifth were as close as I've gotten with a 2 1/2 minute positive. Two were the disasters you hear about - for a mulitple of reasons (excuses?). Perhaps Boston in 2014 I'll try to enjoy the experience and go for a positive split

??? Negative splits is often touted as the method to run an optimum time, so I don't see how it would require less recovery, though I can see that it may be less painful than a positive split, which often is the result of crashing late in a race. If running less than 100% max effort, I wouldn't think it mattered whether one ran positive, negative, or even splits. I see nothing inherent in negative splits that would make that the preferred way to run sub-maximal effort races.

But just think of your own long runs. If you run 20 this weekend at 1:30 over your MGP you probably feel pretty good and are ready to go by Tuesday. But if you run that same 20 next weekend at MGP +15 you are going to be spent, and will need five or more days before you feel like running much again. Right? Same principle.

Aren't negative splits the outcome of a well-executed race, rather than a direct goal ?

Well, some would say they are the sub obtimal result of going out slower than your best pace. If I can run a 3 hour marathon, but run the first half in 2 hours there is no way I'm going to run the second half in 1 hour. More likley I'll run (at best) a 1:15 and finish with a 3:15 - 15 minute negative split, but also 15 minutes from my optimal. I realize this is an extream example, but the principle is the same at any pace.

I'm not sure why there's such a fascination or desire to aim for a negative split in a marathon.

I have the fascination because I usually negative split my races. In the past, I thought I ran too conservative after a negative split. So, the next race I tried an even pace and it was not enjoyable.I wanted to quit. The end really hurt and I ended up with a positive split . The end hurts when I run a negative split, however, it's more enjoyable. Instead of struggling, I have enough energy to reel in the next racer in front of me. It feels good that I can continue increasing my speed towards the end then to be forced to run slow because I can't go faster. It's a good confident builder.

Well, some would say they are the sub obtimal result of going out slower than your best pace. If I can run a 3 hour marathon, but run the first half in 2 hours there is no way I'm going to run the second half in 1 hour. More likley I'll run (at best) a 1:15 and finish with a 3:15 - 15 minute negative split, but also 15 minutes from my optimal. I realize this is an extream example, but the principle is the same at any pace.

Oh, and by the way - +100 to spaniel

An examination of distance WRs since the '70s shows that most were run as negative splits. That doesn't sound sub-optimal to me. It appears that th erace plan is typcially even pace with the negative split the result of being able to finish the last km at a faster pace, i.e. what MilkTruck alluded to.

An examination of distance WRs since the '70s shows that most were run as negative splits. That doesn't sound sub-optimal to me.

First, correct me if I'm wrong, but those "negative WR splits" of which you speak were in the range of seconds (not even 10's of seconds) were they not? I don't believe that's what we are talking about here.

Secondly, WR's aren't run by those of us posting on RA. Those people have a body muscle mass index and a VO2 max that we can't even dream of. Their livers contain a much higher density of glycogen as do their muscles. They do not run low on glycogen stores at the marathon distance.

And third, yes from a pure scientific model, they were sub optimal. If the course was perfectly flat, there was no wind, and no other outside forces, to run anything less than even paced miles for all 26.2 miles, pure biomechanics would say there was some degree of inefficiency involved. And in heaven we all run sub 2 marathons.

??? Negative splits is often touted as the method to run an optimum time,

People going for an optimum time are aiming for even splits, a negative split in that context is a result of a really good day.

Runners run.

Biking Bad

finnegan begin again

posted: 12/15/2012 at 10:57 AM

Going Postal. Picking off runners in the 2nd half of my 3:15 was a blast. Everyone ahead is a target to be overtaken. It helped to fuel me when the run got to it's darker stages.

It was way better than my 5k PR. I went backwards after the first mile. It was a bit deflating despite the final result.

"... the harder the conflict, the more glorious the triumph. What we obtain too cheap, we esteem too lightly: it is dearness only that gives every thing its value..." Thomas Paine Dec 23, 1776 The Crisis